Many applications such as satellites and light weight robotic aircraft require high frequency electromagnetic transmitters with minimal power requirements. Such transmitters are also utilized to monitor tanks which store radioisotopes, such as Krypton-i5. Powering such transmitters with light weight, long-lifetime sources rather than batters is also advantageous in decreasing weight and system longevity. In U.S. Pat. No. 2,926,268, which is herein incorporated by reference in its entirety, Reymond describes the use of beta electrons emitted from a radioisotope to decrease the power requirements of conventional vacuum diodes. However, that patent does not utilize magnetic fields and is limited to direct current applications that require an external power supply. Southwirth (“Principles and Application of Waveguide Transmission,” G. Southworth, Van Nostrand (1950), herein incorporated by reference in its entirety) and Harmon (“Fundamentals of Electron Motion,” W.H. Harman, McGraw-Hill (1953), herein incorporated by reference in its entirety, discuss the interaction of electron gun beams with magnetic fields such as in traveling wave tubes and other high frequency oscillators. In such devices high frequency power supplies couple energy into the electron beam through a series of resonant cavities thereby increasing the electron energy.
In aspects of the present disclosure, an inverse process is used such that high velocity beta electrons induce currents in resonant cavities to provide an output transmission signal. As described in detail below, the resonant coupling and induced signal generation is accomplished by altering the emitted beta electron trajectory with a homogenous magnetic field such that the electrons enter a cycloid or helical motion with an angular velocity. The electron trajectories induce oscillating currents in a novel resonant cavity structure fabricated from engineering plastic components (for example, metalized plastic) to generate and transmit the high frequency signals.